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2023-05-30aio: remove aio_disable_external() APIStefan Hajnoczi
All callers now pass is_external=false to aio_set_fd_handler() and aio_set_event_notifier(). The aio_disable_external() API that temporarily disables fd handlers that were registered is_external=true is therefore dead code. Remove aio_disable_external(), aio_enable_external(), and the is_external arguments to aio_set_fd_handler() and aio_set_event_notifier(). The entire test-fdmon-epoll test is removed because its sole purpose was testing aio_disable_external(). Parts of this patch were generated using the following coccinelle (https://coccinelle.lip6.fr/) semantic patch: @@ expression ctx, fd, is_external, io_read, io_write, io_poll, io_poll_ready, opaque; @@ - aio_set_fd_handler(ctx, fd, is_external, io_read, io_write, io_poll, io_poll_ready, opaque) + aio_set_fd_handler(ctx, fd, io_read, io_write, io_poll, io_poll_ready, opaque) @@ expression ctx, notifier, is_external, io_read, io_poll, io_poll_ready; @@ - aio_set_event_notifier(ctx, notifier, is_external, io_read, io_poll, io_poll_ready) + aio_set_event_notifier(ctx, notifier, io_read, io_poll, io_poll_ready) Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230516190238.8401-21-stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30block/fuse: do not set is_external=true on FUSE fdStefan Hajnoczi
This is part of ongoing work to remove the aio_disable_external() API. Use BlockDevOps .drained_begin/end/poll() instead of aio_set_fd_handler(is_external=true). As a side-effect the FUSE export now follows AioContext changes like the other export types. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230516190238.8401-16-stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-03-10block/fuse: Let PUNCH_HOLE write zeroesHanna Czenczek
fallocate(2) says about PUNCH_HOLE: "After a successful call, subsequent reads from this range will return zeros." As it is, PUNCH_HOLE is implemented as a call to blk_pdiscard(), which does not guarantee this. We must call blk_pwrite_zeroes() instead. The difference to ZERO_RANGE is that we pass the `BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK` flags to the call -- the storage is supposed to be unmapped, and a slow fallback by actually writing zeroes as data is not allowed. Closes: https://gitlab.com/qemu-project/qemu/-/issues/1507 Signed-off-by: Hanna Czenczek <hreitz@redhat.com> Message-Id: <20230227104725.33511-2-hreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-01-20include/block: Untangle inclusion loopsMarkus Armbruster
We have two inclusion loops: block/block.h -> block/block-global-state.h -> block/block-common.h -> block/blockjob.h -> block/block.h block/block.h -> block/block-io.h -> block/block-common.h -> block/blockjob.h -> block/block.h I believe these go back to Emanuele's reorganization of the block API, merged a few months ago in commit d7e2fe4aac8. Fortunately, breaking them is merely a matter of deleting unnecessary includes from headers, and adding them back in places where they are now missing. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20221221133551.3967339-2-armbru@redhat.com>
2022-07-12block: Change blk_{pread,pwrite}() param orderAlberto Faria
Swap 'buf' and 'bytes' around for consistency with blk_co_{pread,pwrite}(), and in preparation to implement these functions using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression blk, offset, buf, bytes, flags; @@ - blk_pread(blk, offset, buf, bytes, flags) + blk_pread(blk, offset, bytes, buf, flags) @@ expression blk, offset, buf, bytes, flags; @@ - blk_pwrite(blk, offset, buf, bytes, flags) + blk_pwrite(blk, offset, bytes, buf, flags) It had no effect on hw/block/nand.c, presumably due to the #if, so that file was updated manually. Overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-4-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-12block: Add a 'flags' param to blk_pread()Alberto Faria
For consistency with other I/O functions, and in preparation to implement it using generated_co_wrapper. Callers were updated using this Coccinelle script: @@ expression blk, offset, buf, bytes; @@ - blk_pread(blk, offset, buf, bytes) + blk_pread(blk, offset, buf, bytes, 0) It had no effect on hw/block/nand.c, presumably due to the #if, so that file was updated manually. Overly-long lines were then fixed by hand. Signed-off-by: Alberto Faria <afaria@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Greg Kurz <groug@kaod.org> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220705161527.1054072-3-afaria@redhat.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-03-07osdep: Move memalign-related functions to their own headerPeter Maydell
Move the various memalign-related functions out of osdep.h and into their own header, which we include only where they are used. While we're doing this, add some brief documentation comments. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 20220226180723.1706285-10-peter.maydell@linaro.org
2022-03-04block/export/fuse.c: allow writable exports to take RESIZE permissionEmanuele Giuseppe Esposito
Allow writable exports to get BLK_PERM_RESIZE permission from creation, in fuse_export_create(). In this way, there is no need to give the permission in fuse_do_truncate(), which might be run in an iothread. Permissions should be set only in the main thread, so in any case if an iothread tries to set RESIZE, it will be blocked. Also assert in fuse_do_truncate that if we give the RESIZE permission we can then restore the original ones. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20220303151616.325444-7-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-02-01block/export/fuse: Fix build failure on FreeBSDPhilippe Mathieu-Daudé
When building on FreeBSD we get: [816/6851] Compiling C object libblockdev.fa.p/block_export_fuse.c.o ../block/export/fuse.c:628:16: error: use of undeclared identifier 'FALLOC_FL_KEEP_SIZE' if (mode & FALLOC_FL_KEEP_SIZE) { ^ ../block/export/fuse.c:651:16: error: use of undeclared identifier 'FALLOC_FL_PUNCH_HOLE' if (mode & FALLOC_FL_PUNCH_HOLE) { ^ ../block/export/fuse.c:652:22: error: use of undeclared identifier 'FALLOC_FL_KEEP_SIZE' if (!(mode & FALLOC_FL_KEEP_SIZE)) { ^ 3 errors generated. FAILED: libblockdev.fa.p/block_export_fuse.c.o Meson indeed reported FALLOC_FL_PUNCH_HOLE is not available: C compiler for the host machine: cc (clang 10.0.1 "FreeBSD clang version 10.0.1") Checking for function "fallocate" : NO Checking for function "posix_fallocate" : YES Header <linux/falloc.h> has symbol "FALLOC_FL_PUNCH_HOLE" : NO Header <linux/falloc.h> has symbol "FALLOC_FL_ZERO_RANGE" : NO ... Similarly to commit 304332039 ("block/export/fuse.c: fix musl build"), guard the code requiring FALLOC_FL_KEEP_SIZE / FALLOC_FL_PUNCH_HOLE definitions under CONFIG_FALLOCATE_PUNCH_HOLE #ifdef'ry. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20220201112655.344373-3-f4bug@amsat.org> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-02-01block/export/fuse: Rearrange if-else-if ladder in fuse_fallocate()Philippe Mathieu-Daudé
In order to safely maintain a mixture of #ifdef'ry with if-else-if ladder, rearrange the last statement (!mode) first. Since it is mutually exclusive with the other conditions, checking it first doesn't make any logical difference, but allows to add #ifdef'ry around in a more cleanly way. Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20220201112655.344373-2-f4bug@amsat.org> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-01-12aio-posix: split poll check from ready handlerStefan Hajnoczi
Adaptive polling measures the execution time of the polling check plus handlers called when a polled event becomes ready. Handlers can take a significant amount of time, making it look like polling was running for a long time when in fact the event handler was running for a long time. For example, on Linux the io_submit(2) syscall invoked when a virtio-blk device's virtqueue becomes ready can take 10s of microseconds. This can exceed the default polling interval (32 microseconds) and cause adaptive polling to stop polling. By excluding the handler's execution time from the polling check we make the adaptive polling calculation more accurate. As a result, the event loop now stays in polling mode where previously it would have fallen back to file descriptor monitoring. The following data was collected with virtio-blk num-queues=2 event_idx=off using an IOThread. Before: 168k IOPS, IOThread syscalls: 9837.115 ( 0.020 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 16, iocbpp: 0x7fcb9f937db0) = 16 9837.158 ( 0.002 ms): IO iothread1/620155 write(fd: 103, buf: 0x556a2ef71b88, count: 8) = 8 9837.161 ( 0.001 ms): IO iothread1/620155 write(fd: 104, buf: 0x556a2ef71b88, count: 8) = 8 9837.163 ( 0.001 ms): IO iothread1/620155 ppoll(ufds: 0x7fcb90002800, nfds: 4, tsp: 0x7fcb9f1342d0, sigsetsize: 8) = 3 9837.164 ( 0.001 ms): IO iothread1/620155 read(fd: 107, buf: 0x7fcb9f939cc0, count: 512) = 8 9837.174 ( 0.001 ms): IO iothread1/620155 read(fd: 105, buf: 0x7fcb9f939cc0, count: 512) = 8 9837.176 ( 0.001 ms): IO iothread1/620155 read(fd: 106, buf: 0x7fcb9f939cc0, count: 512) = 8 9837.209 ( 0.035 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 32, iocbpp: 0x7fca7d0cebe0) = 32 174k IOPS (+3.6%), IOThread syscalls: 9809.566 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0cdd62be0) = 32 9809.625 ( 0.001 ms): IO iothread1/623061 write(fd: 103, buf: 0x5647cfba5f58, count: 8) = 8 9809.627 ( 0.002 ms): IO iothread1/623061 write(fd: 104, buf: 0x5647cfba5f58, count: 8) = 8 9809.663 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0d0388b50) = 32 Notice that ppoll(2) and eventfd read(2) syscalls are eliminated because the IOThread stays in polling mode instead of falling back to file descriptor monitoring. As usual, polling is not implemented on Windows so this patch ignores the new io_poll_read() callback in aio-win32.c. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Message-id: 20211207132336.36627-2-stefanha@redhat.com [Fixed up aio_set_event_notifier() calls in tests/unit/test-fdmon-epoll.c added after this series was queued. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-11-02block/export/fuse.c: fix musl buildFabrice Fontaine
Include linux/falloc.h if CONFIG_FALLOCATE_ZERO_RANGE is defined to fix https://gitlab.com/qemu-project/qemu/-/commit/50482fda98bd62e072c30b7ea73c985c4e9d9bbb and avoid the following build failure on musl: ../block/export/fuse.c: In function 'fuse_fallocate': ../block/export/fuse.c:643:21: error: 'FALLOC_FL_ZERO_RANGE' undeclared (first use in this function) 643 | else if (mode & FALLOC_FL_ZERO_RANGE) { | ^~~~~~~~~~~~~~~~~~~~ Fixes: - http://autobuild.buildroot.org/results/be24433a429fda681fb66698160132c1c99bc53b Fixes: 50482fda98b ("block/export/fuse.c: fix musl build") Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com> Message-Id: <20211022095209.1319671-1-fontaine.fabrice@gmail.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-09-01block/export/fuse.c: fix fuse-lseek on uclibc or muslFabrice Fontaine
Include linux/fs.h to avoid the following build failure on uclibc or musl raised since version 6.0.0: ../block/export/fuse.c: In function 'fuse_lseek': ../block/export/fuse.c:641:19: error: 'SEEK_HOLE' undeclared (first use in this function) 641 | if (whence != SEEK_HOLE && whence != SEEK_DATA) { | ^~~~~~~~~ ../block/export/fuse.c:641:19: note: each undeclared identifier is reported only once for each function it appears in ../block/export/fuse.c:641:42: error: 'SEEK_DATA' undeclared (first use in this function); did you mean 'SEEK_SET'? 641 | if (whence != SEEK_HOLE && whence != SEEK_DATA) { | ^~~~~~~~~ | SEEK_SET Fixes: - http://autobuild.buildroot.org/results/33c90ebf04997f4d3557cfa66abc9cf9a3076137 Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com> Message-Id: <20210827220301.272887-1-fontaine.fabrice@gmail.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-08-09block/export/fuse.c: fix musl buildFabrice Fontaine
Fix the following build failure on musl raised since version 6.0.0 and https://gitlab.com/qemu-project/qemu/-/commit/4ca37a96a75aafe7a37ba51ab1912b09b7190a6b because musl does not define FALLOC_FL_ZERO_RANGE: ../block/export/fuse.c: In function 'fuse_fallocate': ../block/export/fuse.c:563:23: error: 'FALLOC_FL_ZERO_RANGE' undeclared (first use in this function) 563 | } else if (mode & FALLOC_FL_ZERO_RANGE) { | ^~~~~~~~~~~~~~~~~~~~ Fixes: - http://autobuild.buildroot.org/results/b96e3d364fd1f8bbfb18904a742e73327d308f64 Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com> Message-Id: <20210809095101.1101336-1-fontaine.fabrice@gmail.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-07-09export/fuse: Let permissions be adjustableMax Reitz
Allow changing the file mode, UID, and GID through SETATTR. Without allow_other, UID and GID are not allowed to be changed, because it would not make sense. Also, changing group or others' permissions is not allowed either. For read-only exports, +w cannot be set. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210625142317.271673-5-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-07-09export/fuse: Give SET_ATTR_SIZE its own branchMax Reitz
In order to support changing other attributes than the file size in fuse_setattr(), we have to give each its own independent branch. This also applies to the only attribute we do support right now. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210625142317.271673-4-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-07-09export/fuse: Add allow-other optionMax Reitz
Without the allow_other mount option, no user (not even root) but the one who started qemu/the storage daemon can access the export. Allow users to configure the export such that such accesses are possible. While allow_other is probably what users want, we cannot make it an unconditional default, because passing it is only possible (for non-root users) if the global fuse.conf configuration file allows it. Thus, the default is an 'auto' mode, in which we first try with allow_other, and then fall back to without. FuseExport.allow_other reports whether allow_other was actually used as a mount option or not. Currently, this information is not used, but a future patch will let this field decide whether e.g. an export's UID and GID can be changed through chmod. One notable thing about 'auto' mode is that libfuse may print error messages directly to stderr, and so may fusermount (which it executes). Our export code cannot really filter or hide them. Therefore, if 'auto' fails its first attempt and has to fall back, fusermount will print an error message that mounting with allow_other failed. This behavior necessitates a change to iotest 308, namely we need to filter out this error message (because if the first attempt at mounting with allow_other succeeds, there will be no such message). Furthermore, common.rc's _make_test_img should use allow-other=off for FUSE exports, because iotests generally do not need to access images from other users, so allow-other=on or allow-other=auto have no advantage. OTOH, allow-other=on will not work on systems where user_allow_other is disabled, and with allow-other=auto, we get said error message that we would need to filter out again. Just disabling allow-other is simplest. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210625142317.271673-3-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-07-09export/fuse: Pass default_permissions for mountMax Reitz
We do not do any permission checks in fuse_open(), so let the kernel do them. We already let fuse_getattr() report the proper UNIX permissions, so this should work the way we want. This causes a change in 308's reference output, because now opening a non-writable export with O_RDWR fails already, instead of only actually attempting to write to it. (That is an improvement.) Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210625142317.271673-2-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-11fuse: Implement hole detection through lseekMax Reitz
This is a relatively new feature in libfuse (available since 3.8.0, which was released in November 2019), so we have to add a dedicated check whether it is available before making use of it. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20201027190600.192171-7-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-11fuse: (Partially) implement fallocate()Max Reitz
This allows allocating areas after the (old) EOF as part of a growing resize, writing zeroes, and discarding. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20201027190600.192171-6-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-11fuse: Allow growable exportsMax Reitz
These will behave more like normal files in that writes beyond the EOF will automatically grow the export size. As an optimization, keep the RESIZE permission for growable exports so we do not have to take it for every post-EOF write. (This permission is not released when the export is destroyed, because at that point the BlockBackend is destroyed altogether anyway.) Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20201027190600.192171-5-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-11fuse: Implement standard FUSE operationsMax Reitz
This makes the export actually useful instead of only producing errors whenever it is accessed. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20201027190600.192171-4-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-11fuse: Allow exporting BDSs via FUSEMax Reitz
block-export-add type=fuse allows mounting block graph nodes via FUSE on some existing regular file. That file should then appears like a raw disk image, and accesses to it result in accesses to the exported BDS. Right now, we only implement the necessary block export functions to set it up and shut it down. We do not implement any access functions, so accessing the mount point only results in errors. This will be addressed by a followup patch. We keep a hash table of exported mount points, because we want to be able to detect when users try to use a mount point twice. This is because we invoke stat() to check whether the given mount point is a regular file, but if that file is served by ourselves (because it is already used as a mount point), then this stat() would have to be served by ourselves, too, which is impossible to do while we (as the caller) are waiting for it to settle. Therefore, keep track of mount point paths to at least catch the most obvious instances of that problem. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20201027190600.192171-3-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>